Hot melt ink compositions

ABSTRACT

A ink composition comprised of (1) a liquid cyclic vehicle (2) a cyclic compound, (3) a liquid crystalline nitrile compound, (4) a lightfastness UV absorber, (5) a lightfastness antioxidant, and (6) a colorant.

This application is a continuation of application Ser. No. 08/933,914,filed Sep. 23, 1997.

REFERENCE TO COPENDING PATENT APPLICATIONS AND PATENTS

Hot melt inks are illustrated in U.S. Pat. No. 5,683,312, U.S. Pat. No.5,667,568, U.S. Pat. No. 5,700,316, U.S. Pat. No. 5,747,554, and U.S.Ser. No. 641,866 (D/95458), the disclosures of each being totallyincorporated herein by reference.

Disclosed in copending applications filed currently herewith, U.S. Ser.Nos. 08/935,929, 08/935,889, 08/935,639 and 08/936,084, the disclosuresof each application being totally incorporated herein by reference, arehot melt inks.

Ink components, such as the colorants, of the copending applicaitons maybe selected for the inks of the present invention in embodimentsthereof.

BACKGROUND OF THE INVENTION

The present invention is directed to ink compositions and, morespecifically, the present invention relates to hot melt inks with forexample, a melting point of between about 25° C. and about 50, andpreferably about 40° C., and which inks are especially useful foracoustic ink printing, processes and apparatuses, reference, forexample, U.S. Pat. No. 5,121,141, U.S. Pat. No. 5,111,220, U.S. Pat. No.5,128,726, U.S. Pat. No. 5,371,531, the disclosures of which are totallyincorporated herein by reference, including especially acoustic inkprocesses as illustrated in some of the aforementioned copendingapplications and patents, such as an acoustic ink printer for printingimages on a record medium.

The inks of the present invention in embodiments thereof are comprisedof (1) a liquid non-aqueous vehicle with for example, a boiling point ofhigher than, or equal to about 150° C. (Centigrade) and lower than, orequal to about 350° C., and more sepcifically from about 175 to about325, and yet more specifically from about 225 to about 300 degreesCentigrade, with a low acoustic loss, which enables for example, areduction, or minimzation of energy consumption, and which acoustic lossis below, or about equal to about 60 dB/mm, (2) a solid color spreadingcompound, or paper additive contained in the substrate, such as thepaper pores, and which compound has a melting point of lower than, orequal to about 75° C. and preferably between about 30 to about 74° C.,and with a low acoustic loss value of below about, or equal to about 100dB/mm, (3) a nitrile liquid crystalline compound, (4) a light fastnessUV absorber, (5) a light fastness antioxidant, (6) and a colorant suchas a dye, a pigment or mixtures thereof. More specifically, the presentinvention is directed to semi-solid hot melt acoustic ink compositionscomprised of (1) non-aqueous liquid vehicles with a boiling point ofhigher than about 150° C. and lower than about 350° C., preferablybetween about 170 to about 300° C., and with low acoustic loss, andwhich acoustic loss is below about, or equal to about 60 dB/mm, andpreferably in the range of between about 5 to about 40 dB/mm, (2) anon-aqueous solid, preferably cyclic additive with a melting point oflower than about 75° C. and preferably between about 30 and about 74°C., and with low acoustic loss and which acoustic loss is below about,or equal to about 100 dB/mm, and preferably in the range of betweenabout 25 to about 80 dB/mm, (3) a liquid crystalline nitrile compound,(4) a UV absorber, (5) an antioxidant, and (6) a colorant, and whereinthere can be generated with such inks excellent developed images onplain and coated papers with acceptable image permanence, excellentprojection efficiency on transparencies without a post fusing step, andexcellent crease resistance, and wherein the inks possess acceptable,and in embodiments superior lightfastness, and superior waterfastness.Moreover, in embodiments of the present invention there is enabled theelimination, or minimization of undesirable paper curl since water isnot present, or minium amounts of water may be selected in embdoiments,and it is preferred that there be an absence of water. When water is notpresent in the inks a dryer can be avoided thereby minimizing the costof the acoustic ink jet apparatus and process.

PRIOR ART

In acoustic ink printing, the printhead produces approximately 2.2picoliter droplets by an acoustic energy process. The ink under theseconditions should display a melt viscosity of from about 5 to about 20centipoise or less at the jetting temperature. Furthermore, once the inkis jetted onto the paper, the ink image should be of excellent creaseproperty, and should be nonsmearing, waterfast, of excellenttransparency and excellent fix qualities. In selecting an ink for suchapplications, it is desirable that the vehicle display a low meltviscosity, such as from about 1 centipoise to about 25 centipoise in theacoustic head, while also displaying solid like properties after beingjetted onto paper. Since the acoustic head can tolerate a temperature upto about 180° C., and preferably up to a temperature of from about 140°C. to about 160° C., the vehicle for the ink should preferably displayliquid like properties, such as a viscosity of 1 to about 10 centipoiseat a temperature of from about 75° C. to about 165° C., and solidify orharden after jetting onto paper such that the ink displays a hardnessvalue of for example, from about 0.1 to about 0.5 millimeter utilizing apenetrometer according to the ASTM penetration method D1321.

Ink jet printing processes that employ inks that are solid at roomtemperature and liquid at elevated temperatures are known. For example,U.S. Pat. No. 4,490,731, the disclosure of which is totally incorporatedherein by reference, discloses an apparatus for dispensing certain solidinks for printing on a substrate such as paper. The ink dye vehicle ischosen to have a melting point above room temperature so that the inkwhich is melted in the apparatus will not be subject to evaporation orspillage during periods of nonprinting. The vehicle selected possesses alow critical temperature to permit the use of the solid ink in a thermalink jet printer. In thermal ink jet printing processes employingsemi-solid hot melt inks, the solid ink is melted by a heater in theprinting apparatus and utilized as a liquid in a manner similar to thatof conventional thermal ink jet printing. Upon contact with the printingsubstrate, the molten ink solidifies rapidly, enabling the dye to remainon the surface instead of being carried into the paper by capillaryaction, thereby attempting to enable higher print density than isgenerally obtained with liquid inks. Semi-solid hot melt ink jets aresomewhat similar to thermal ink jets, however, a semi-solid hot melt inkcontains no solvent. Thus, rather than being liquid at room temperature,a semi-solid hot melt ink is typically a solid or semi-solid having awax-like consistency. These inks usually need to be heated, for example,to approximately 100° C. before the ink melts and turns into a liquid.With semi-solid hot melt inks, a plurality of ink jet nozzles areprovided in a printhead. A piezoelectric vibrating element is located ineach ink channel upstream from a nozzle so that the piezoelectricoscillations propel ink through the nozzle. After the semi-solid hotmelt ink is applied to the substrate, the ink is resolidified byfreezing on the substrate.

Each of these types of known ink jets, however, has a number ofadvantages and disadvantages. One advantage of thermal ink jets is theircompact design for the integrated electronics section of the printhead.Thermal ink jets are disadvantageous in that the thermal ink has atendency to soak into a plain paper medium. This blurs the print orthins out the print locally thereby adversely affecting print quality.Problems have been encountered with thermal ink jets in attempting toeliminate moisture fast enough so that the ink does not soak into aplain paper medium. This is particularly the situation when printingwith color.

One advantage of a semi-solid hot melt ink jet is its ability to printon plain paper since the semi-solid hot melt ink quickly solidifies asit cools and, as it is waxy in nature it does not normally soak into apaper medium. However, semi-solid hot melt ink jets can be cumbersome instructure and in design, that is, the associated integrated electronicsof a thermal ink jet head are considerably more compact than those of asemi-solid hot melt ink jet head.

In addition, U.S. Pat. No. 4,751,528, the disclosure of which is totallyincorporated herein by reference, discloses a semi-solid hot melt inkjet system which includes a temperature-controlled platen provided witha heater and a thermoelectric cooler electrically connected to a heatpump and a temperature control unit for controlling the operation of theheater and the heat pump to maintain the platen temperature at a desiredlevel.

Further, U.S. Pat. No. 4,791,439, the disclosure of which is totallyincorporated by reference, discloses an apparatus for use withsemi-solid hot melt inks with an integrally connected ink jet head andreservoir system, the reservoir system including a highly efficient heatconducting plate inserted within an essentially nonheat conductingreservoir housing.

Ink compositions for ink jet printing are known. For example, U.S. Pat.No. 4,840,674, the disclosure of which is totally incorporated herein byreference, discloses an ink composition which comprises a major amountof water, an organic solvent selected from the group consisting oftetramethylene sulfone, 1,1,3,3-tetramethyl urea, 3-methyl sulfolane,and 1,3-dimethyl-2-imidazolidone, which solvent has permanentlydissolved therein spirit soluble dyes.

U.S. Pat. No. 5,006,170 and U.S. Pat. No. 5,122,187, the disclosures ofeach of which are totally incorporated herein by reference, disclose hotmelt ink compositions suitable for ink jet printing which comprise acolorant, a binder, and a propellant such as hydrazine, cyclic amines,ureas, carboxylic acids, sulfonic acids, aldehydes, ketones,hydrocarbons, esters, phenols, amides, imides, halocarbons, and thelike.

U.S. Pat. No. 5,041,161, the disclosure of which is totally incorporatedherein by reference, discloses an ink jet ink which is semi-solid atroom temperature. The inks comprise vehicles, such as acids, aldehydesand mixtures thereof, which are semi-solid at temperatures between 20°C. and 45° C. The ink is impulse jetted at an elevated temperature inthe range of about 45° C. to about 110° C., at which temperature the inkhas a viscosity of about 10 to 15 centipoise. The inks also contain 0.1to 20 weight percent of a colorant system.

U.S. Pat. No. 4,853,036 and U.S. Pat. No. 5,124,718 disclose an ink forink jet recording which comprises a liquid composition essentiallycomprising a coloring matter, a volatile solvent with a vapor pressureof 1 millimeter Hg or more at 25° C., and a compound being solid at roomtemperature and having a molecular weight of 300 or more, and preparedso as to satisfy the formula illustrated in this patent.

SUMMARY OF THE INVENTION

While the known ink compositions and processes may be suitable for theirintended purposes, a need remains for acoustic semi-solid hot melt inkcompositions suitable for thermal ink jet printing. In addition, thereis a need for semi-solid hot melt ink compositions which are compatiblewith a wide variety of plain papers and yield photographic qualityimages on coated papers. Further, there is a need for semi-solid hotmelt ink compositions which generate high quality, lightfast, andwaterfast images on plain papers. There is also a need for semi-solidhot melt ink jet ink compositions which generate high quality,fast-drying images on a wide variety of plain papers at low cost withhigh quality text and high quality graphics, and wherein the the dye isretained on the paper surface while the ink vehicle can continue tospread within the paper structure. Further, there is a need forsemi-solid semi-solid hot melt ink jet ink compositions which exhibitminimal feathering. Additionally, there is a need for semi-solid hotmelt ink jet ink compositions which exhibit minimal intercolor bleed.There is also a need for semi-solid hot melt ink jet ink compositionswhich possess excellent image permanence. Further, there is a need forsemi-solid semi-solid hot melt ink jet ink compositions which aresuitable for use in acoustic ink jet printing processes. Additionally,there is a need for semi-solid hot ink compositions suitable for ink jetprinting processes wherein the substrate is heated prior to printing andis cooled to ambient temperature subsequent to printing (heat and delayprinting processes). There is also a need for ink compositions suitablefor ink jet printing wherein high optical densities can be achieved withrelatively low dye concentrations. A need also remains for inkcompositions suitable for ink jet printing wherein curling of thesubstrate, such as paper, subsequent to printing is minimized, oravoided. These and other needs can be achievable with the inks of thepresent invention in embodiments thereof.

DETAILED DESCRIPTION OF THE INVENTION

The invention of the present application in embodiments relates to anink composition comprised of (1) a liquid cyclic vehicle (2) a cyclic,preferably solid cyclic compound, (3) a liquid crystalline nitritecompound, (4) a lightfastness UV absorber, (5) a lightfastnessantioxidant, and (6) a colorant.

In embodiments the ink compositions of the present invention comprise acolorant, such as a dye, and a cyclic liquid vehicle with for example,an acoustic-loss value of from about 5 to about 40 dB/mm and a boilingpoint of for example, greater than, or equal to about 150° C. and lowerthan about 350° C., and preferably between about 170 to about 300° C.,and with low acoustic loss values of for example, below, or equal toabout 60 dB/mm, and preferably in the range of between about 5 to about40 dB/mm, (2) a non-aqueous solid, preferably cyclic additive with forexample, a melting point of lower than, or equal to about 75° C. andpreferably between about 30 to about 74° C., with a low acoustic lossvalue, and which acoustic loss is for example, below about, or equal toabout 100 dB/mm, and preferably in the range of between about 25 toabout 80 dB/mm, (3) a liquid crystalline nitrile compound, (4) a UVabsorber, and (5) an antioxidant, each present in various suitableamounts.

In embodiments, the inks possess a viscosity of from, for example, about1 to about 20, and preferably from 1 to about 10 centipoise.

The present invention relates to a substantially nonaqueous inkcomposition comprised of (1) a liquid cyclic vehicle with anacoustic-loss value of from about 5 to about 40 dB/mm, (2) a solidadditive component with a melting point of from about 30 to about 74° C.and an acoustic-loss value of from about 25 to about 80 dB/mm, (3) aliquid crystalline nitrile compound, (4) a lightfastness UV absorber,(5) a lightfastness antioxidant, and (6) a colorant, and which inkpossesses an acoustic-loss value of from about 10 to about 80 dB/mm; anonaqueous ink composition wherein the cyclic vehicle is present in anamount of from about 0.5 to about 49 percent by weight, the solidadditive component with a melting point of from about 30 to about 74° C.is present in an amount of from about 0.5 to about 49 percent by weight,the liquid crystalline nitrile compound is present in an amount of fromabout 69 to about 1 percent by weight, the UV absorber is present in anamount of from about 5 to about 0.25 percent by weight, the antioxidantis present in an amount of from about 5 to about 0.25 percent by weight,and the colorant is present in an amount of from about 20 to about 0.5percent by weight; a nonaqueous ink composition wherein the liquidcyclic vehicle is selected from the group consisting of cyclic compoundsof (1) 1,2,2,6,6-pentamethyl piperidine, (2) indan, (3) indene, (4)4-(2-aminoethyl)morpholine (5) 1-(3-aminopropyl)-2-pyrrolidone, (6)ethylβ-oxo-3-furanpropionate, (7) tetrahydrofurfuryl alcohol, (8) methyl2-furoate, (9) 2-methoxy-5-methylpyrazine (10)4,8-bis(hydroxymethyl)tricyclo [5.2.1.0².6 ] decane, and (11)01-acetyl-2-methyl-1-cyclopentene; a nonaqueous ink composition whereinthe liquid cyclic vehicle is selected from the group consisting ofanhydrides of (1) butyric anhydride, (2) valeric anhydride (3) hexanoicanhydride, (4) heptanoicanhydride, (5) decanoicanhydride, (6) dodecenylsuccinic anhydride, (7) bromomaleicanhydride, (8) citraconic anhydride,(9) 4-methyl-1,2-cyclohexane dicarboxylic anhdride, and (10)methyl-5-norbornene-2,3-dicarboxylic anhydride; a nonaqueous inkcomposition wherein the solid additive (2) is a heterocyclic compoundselected from the group consisting of (1) 5-(hydroxymethyl)furfural, (2)1,2-bis(4,4-dimethyl-2-oxazolin-2-yl)ethane, (3) dimethyl-3,4-furanedicarboxylate, (4) methyl 2,5-dihydro-2,5-dimethoxy-2-furan carboxylate,(5) tert-butyl-4-benzyl-1-piperazinecarboxylate, (6) (S)-(-)-5-(hydroxymethyl)-2(5H)furanone, (7) 2,4,8,10-tetra oxa spiro [5.5]undecane, (8)3,9-divinyl-2,4,8,10-tetra oxaspiro [5,5]undecane, (9) indole, and (10)2-(4-pentylphenyl)-5-(4-pentyloxyphenyl) pyrimidine; a nonaqueous inkcomposition wherein the additive (2) with a melting point of from about30 to about 74° C. is selected from the group consisting of (1)2,2-dimethyl succinic anhydride, (2) 2-dodecen-1-yl succinic anhydride,(3) cis-1,2-cyclohexane dicarboxylic anhydride, (4) 2,2-dimethylglutaric anhydride, (5) 1-cyclopentene-1,2-dicarboxylic anhydride, (6)myristic anhydride, (7) glutaric anhydride, (8)(S)-(-)-2-acetoxysuccinic anhydride, (9) 3,3-tetramethylene glutaricanhydride, and (10)stearic anhydride; a nonaqueous ink compositionwherein the nitrile liquid crystalline compound is selected from thegroup consisting of (1) 4-(trans-4-pentyl cyclohexyl) benzo nitrile, (2)4'-pentyl-4'-biphenylcarbonitrile, (3) 4'-(pentyloxy)-4-biphenylcarbonitrile, (4) 4'-hexyl-4-biphenylcarbonitrile, (5)4'-(hexyloxy)-4-biphenylcarbonitrile, (6)4'-heptyl-4-biphenylcarbonitrile, (7) 4'-heptyloxy-4-biphenylcarbonitrile, (8) 4'-octyl-4-biphenylcarbonitrile, (9)4'-(octyloxy)-4-biphenyl carbonitrile, and (10) 1-isothiocyanato-4-(trans-4-propylcyclohexyl)benzene; an ink wherein thelightfast UV absorber compound is selected from the group consisting of(1) N-p-ethoxycarbonyl phenyl)-N'-ethyl-N'-phenyl formadine, (2)1,1-(1,2-ethane-diyl) bis(3,3,5,5-tetramethyl piperazinone), (3)6-ethoxy-1,2-dihydro-2,2,4-trimethyl quinoline, (4)2-(4-benzoyl-3-hydroxyphenoxy)ethyl acrylate, (5)2-dodecyl-N-(2,2,6,6-tetramethyl-4-piperidinyl)succinimide, (6)2-dodecyl-N-(1,2,2,6,6-penta methyl-4-piperidinyl)succinimide, (7)N-(1-acetyl-2,2,6,6-tetramethyl-4-piperidinyl)-2-dodecyl succinimide,(8)[2,2,6,6-tetramethyl-4-piperidinyl/β,β,β',β'-tetramethyl-3,9-(2,4,8,10-tetraoxospiro(5,5)undecane)diethyl]-1,2,3,4-butanetetracarboxylate,(9)[1,2,2,6,6-pentamethyl-4-piperidinyl/β,β,β',β"-tetramethyl-3,9-(2,4,8,10-tetraoxospiro (5,5) undecane)diethyl]-1,2,3,4-butane tetracarboxylate, and (10)[2,2,6,6-tetramethyl-4-piperidinyl)-1,2,3,4-butanetetra carboxylate; anonaqueous ink wherein the lightfastness antioxidant is selected fromthe group consisting of (1) antimony dialkyl phosphorodithioate, (2)molybdenum oxysulfide dithio carbamate, (3)nickel-bis(o-ethyl(3,5-di-tert-butyl-4-hydroxybenzyl)phosphonate, and(4) tetra sodium N-(1,2-dicarboxyethyl)-N-octadecyl sulfosuccinamate; anonaqueous ink further containing ink additives; a printing processwhich comprises incorporating into an acoustic ink jet printer the inkillustrated herein, and causing droplets of the ink to be ejected inimagewise pattern onto a substrate; a process which comprises (a)providing an acoustic ink printer having a pool of the liquid inkillustrated herein with a free surface, and a printhead including atleast one droplet ejector for radiating the free surface of said inkwith focused acoustic radiation to eject individual droplets of inktherefrom on demand, said radiation being brought to focus with a finitewaist diameter in a focal plane, and causing droplets of the ink to beejected in imagewise pattern onto a substrate; an ink wherein thecolorant is selected in an amount of from about 0.5 to about 20 percentby weight; an ink wherein the colorant is a pigment, or a dye; an inkwherein the colorant is a pigment of carbon black; an ink wherein thecolorant is a dye of cyan, magneta, yellow, black, or mixtures thereof;an ink wherein (1) the cyclic vehicle is1-acetyl-2-methyl-1-cyclopentene, 1,2,2,6,6-pentamethylpiperidine, orbutyric anhydride, (2) the additive is 2,4,8,10-tetra oxaspiro[5.5]undecane, or 1,2-bis(4,4-dimethyl-2-oxazolin-2-yl)ethanestearic anhydride, (3) the liquid crystalline nitrile compound is4'-(pentyloxy)-4-biphenylcarbonitrile, or4'-(pentyloxy)-4-biphenylcarbonitrile, (4) the UV absorber is2-dodecyl-N-(2,2,6,6-tetramethyl-4-piperidinyl) succinimide, or[1,2,2,6,6-pentamethyl-4-piperidinyl/β,β,β',β'tetramethyl-3,9-(2,4,8,10-tetraoxospiro (5,5) undecane)diethyl]-1,2,3,4-butane tetracarboxylate, (5) thelightfastness antioxidant istetra-sodium-N-(1,2-dicarboxyethyl)-N-octadecyl-sulfosuccinamate), ormolybdenum oxysulfide dithio carbamate; an ink with a viscosity of fromabout 1 centipoise to about 10 centipoise at a temperature of from about125° C. to about 165° C.; an ink composition comprised of (1) a liquidcyclic vehicle (2) a cyclic compound, (3) a liquid crystalline nitrilecompound, (4) a lightfastness UV absorber, (5) a lightfastnessantioxidant, and (6) a colorant; an ink wherein the colorant is apigment; an wherein the colorant is a dye; an ink with an acoustic-lossvalue of from about 5 to about 40 dB/mm for said cyclic liquid vehicle,(2) a solid additive cyclic component with a melting point of from about30 to about 74° C. and an acoustic-loss value of from about 25 to about80 dB/mm, and which ink possesses an acoustic-loss value of from about10 to about 80 dB/mm, and which ink possesses a viscosity of from about1 centipoise to about 10 centipoise at a temperature of from about 125°C. to about 165° C.; and an ink wherein the additive (2) is a cyclicsolid compound.

The liquid cyclic vehicle with an acoustic-loss value of for example,from about 5 to about 80, preferably to about 40 dB/mm is present in theink composition in an amount of for example, from about 0.5 to about 49percent by weight, the solid cyclic compound with for example, a meltingpoint of from about 30 to about 74° C. is present for example, in anamount of from about 0.5 to about 49 percent by weight, the nitrileliquid crystalline compound is present for example, in an amount of fromabout 69 to about 1 percent by weight, the UV absorber is present forexample, in an amount of from about 5 to about 0.25 percent by weight,the antioxidant is for example, present in an amount of from about 5 toabout 0.25 percent by weight, and the colorant is for example, presentin an amount of from about 20 to about 0.5 percent by weight, andwherein the total of all ink components is about 100 percent, or about100 parts.

The ink composition contains for example the following range amounts inthe sequence (1), (2), (3), (4), (5), and (6) colorant:[0.5+0.5+69+5+5+20=100] to [49+49+1+0.25+0.25+0.5=100].

In preferred embodiments the liquid cyclic vehicle with an acoustic-lossvalue of from about 5 to about 40 dB/mm is present in an amount of fromabout 5 to about 45 percent by weight, the solid additive cycliccompound having a melting point of for example, from about 30 to about74° C. is present in an amount of from about 5 to about 45 percent byweight, the liquid crystalline nitrile compound is present in an amountof from about 65 to about 7 percent by weight, the UV absorber ispresent in an amount of from about 5 to about 1 percent by weight, theantioxidant is present in an amount of from about 5 to about 1 percentby weight, and the colorant is present in an amount of from about 15 toabout 1 percent by weight. The ink composition contains the followingpreferred range amounts in the aforementioned sequence:[5+5+65+5+5+15=100] to [45+45+7+1+1+1=100]. These composition ranges,and the others indicated herein were established using a number of knowntechniques, such as a statistical design based on the analyses of theexperimental data of viscosity at 150° C., jettability at 150° C., imagequality, lightfastness, and waterfastness characteristics of various inkcompositions.

Embodiments of the present invention include an ink compositioncomprised of a liquid cyclic vehicle with an acoustic-loss value of fromabout 5 to about 40 dB/mm and which cyclic vehicle is selected fromliquid heterocyclics including for example (1) 1-octyl-2-pyrrolidinone,(2) 1-dodecyl-2-pyrrolidinone, (3) 4,4'-trimethylene bis(1-methylpiperidine)piperidine, (4) 4-amino-2,2,6,6-tetramethyl piperidine, (5)1,2,2,6,6-pentamethyl piperidine, (6) 1-acetyl-3-methyl piperidine, (7)5-methylfurfural, (8) 2-methylbenzofuran, (9) 2-acetyl thiophene, (10)3-acetyl pyridine, (11) 4-acetyl pyridine, (12) 1-acetyl-4-piperidone(13) indan, (14) indene, (15) 4-(2-aminoethyl)morpholine, (16)1-(2-amino ethyl)piperazine, (17) 4-(3-aminopropyl)morpholine, (18)1-(2-amino ethyl) piperidine, (19) 4-(aminomethyl)piperidine, (20)2-acetyl-1-methylpyrrole, (21) 3-acetyl-1-methylpyrrole, (22)1-acetylindole, (23) 5-acetyl-2,4-dimethylthiazole, (24)1-(3-aminopropyl)-2-pyrrolidone, (25) benzylpyridine, (26) 5-methoxyindan, (27) ethyl-β-oxo-3-furanpropionate, (28)2-furaldehydediethylacetal, (29) furfuryl acetate, (30)2,5-dimethoxy-2,5-dihydrofuran, (31) 2-acetyl-5-methylfuran, (32)diethyl-3,4-furan dicarboxylate, (33) 2,3-dihydrobenzofuran, (34)3-hydroxy tetrahydrofuran, (35) (±)-2-ethyoxy-tetrahydrofuran, (36)2,5-diethoxytetrahydro furan, (37) tetrahydrofurfuryl alcohol, (38)methyl 2-furoate, (39) 2-acetyl pyridine, (40) 4-acetylmorpholine, (41)2-methoxy-5-methylpyrazine, (42) 2,5-dimethyl pyrazine, (43) and4,8-bis(hydroxymethyl)tricyclo[5.2.1.0².6 ]decane (44) 4-methoxybenzylidene-4'-n-butylaniline, all available from Aldrich chemicals.

Embodiments of the present invention include an ink compositioncomprised of a liquid cyclic vehicle with for example an acoustic-lossvalue of less than about 50, and preferably less thna about 40 dB/mm andwhich vehicle includes liquid cyclic anhydride compounds of (1)butyricanhydride, (2) valeric anhydride, (3) hexanoic anhydride, (4)heptanoic anhydride, (5) decanoicanhydride, (6) dodecenyl succinicanhydride, (7) bromo maleic anhydride, (8) citraconic anhydride, (9)4-methyl-1,2-cyclohexane dicarboxylic anhdride, and (10)methyl-5-norbornene-2,3-dicarboxylic anhydride, all available fromAldrich chemicals.

The compounds (2) preferably with melting points of for example, betweenabout 30 to about of 74° C. and preferably an acoustic-loss value ofbetween 25 to about 80 dB/mm include (1) 1-acetyl piperazine, (2)5-(hydroxy methyl)furfural, (3) 3-acetyl-2,5-dimethylthiophene, (4)ethyl-2-furoate, (5) 3-amino pyrazole, (6) 2-methoxydibenzofuran, (7)3-amino-5-methylpyrazole, (8) 2-amino-4-methylthiazole, (9)5-amino-1-ethylpyrazole, (10) 5-acetoxymethyl-2-furaldehyde, (11)4-acetyl-2,4-dihydro-5-methyl-2-phenyl-3H-pyrazol-3-one monohydrate,(12) 2-acetyl-5-chlorothiophene, (13)1,2-bis(4,4-dimethyl-2-oxazolin-2-yl)ethane, (14) aminopyridine, (15)4,4'-trimethylene dipyridine, (16) 2-amino-4,6-dimethyl pyridine, (17)3-acetyl thiophene, (18) 4,4'-trimethylene dipiperidine, (19) 5-indanol,(20) 2-indanol, (21) 1-indanol, (22) 3-amino-5-methylisoxazole, (23)2-amino-4-phenyl-5-tetra decyl-thiazole, (24)dimethyl3,4-furandicarboxylate, (25)methyl2,5-dihydro-2,5-dimethoxy-2-furancarboxylate, (26)tert-butyl-4-benzyl-1-piperazinecarboxylate, (27)5-(hydroxymethyl)-2(5H)furanone, (28) 2-coumaranone, (29) 3-acetyl-2-oxazolidinone, (30) 1-indanone, (31) 2-indanone, (32) ε-caprolactam, (33)L-α-amino-ε-caprolactam, (34) N-methylsuccinimide, (35)2,4,8,10-tetraoxaspiro[5.5]undecane, (36)3,9-divinyl-2,4,8,10-tetraoxaspiro[5,5]undecane, (37) indole, (38) and2-(4-pentyl phenyl)-5-(4-pentyloxyphenyl)pyrimidine, all availablefromAldrich chemicals.

The additive compounds (2) with a melting point of for example, betweenabout 30 to about of 74° C. and preferably an acoustic-loss value ofbetween 25 to about 80 dB/mm also include (1) 2,2-dimethyl succinicanhydride, (2) methyl succinic anhydride, (3) 2-dodecen-1-yl succinicanhydride, (4) is-1,2-cyclohexane dicarboxylic anhydride, (5) lauricanhydride, (6) 2,2-dimethyl glutaric anhydride, (7) benzoic anhydride,(8) 3-methyl glutaric anhydride, (9)1-cyclopentene-1,2-dicarboxylicanhydride, (10) myristicanhydride, (11)maleic anhydride, (12) glutaricanhydride, (13)(S)-(-)-2-acetoxysuccinicanhydride, (14) palmitic anhydride, (15)3,3-tetramethylene glutaric anhydride, (16) 2 methylene succinicanhydride, and (17) stearic anhydride, all available from Aldrichchemicals.

The nitrile functionality containing liquid crystalline components, orliquid crystalline compounds (3) of the inks are for example, selectedfrom the group consisting of (a) nitrile functional materials such as(1) 4-(trans-4-pentylcyclohexyl)benzonitrile, (2) 4'-pentyl-4'-biphenylcarbonitrile, (3) 4'-(pentyloxy)-4-biphenylcarbonitrile, (4)4'-hexyl-4-biphenyl carbonitrile, (5)4'-(hexyloxy)-4-biphenylcarbonitrile, (6) 4'-heptyl-4-biphenylcarbonitrile, (7) 4'-heptyl oxy-4-biphenyl carbonitrile, (8)4'-octyl-4-biphenyl carbonitrile, (9)4'-(octyloxy)-4-biphenylcarbonitrile, (b) isonitrile compounds (1)1-isothiocyanato-4-(trans-4-propyl cyclohexyl)benzene, (2)1-(trans-4-hexylcyclohexyl)-4-isothiocyanato benzene, (3)1-isothiocyanato-4-(trans-4-octylcyclohexyl) benzene, and (4)1-hexyl-4-(4-isothio cyanato phenyl) bicyclo[2.2.2]octane, all availablefrom Aldrich chemicals.

The lightfast UV absorbers include (1)N-p-ethoxycarbonylphenyl)-N'-ethyl-N'-phenylformadine, GivaudanCorporation, (2) 1,1-(1,2-ethanediyl)bis(3,3,5,5-tetramethylpiperazinone), Goodrich chemicals, (3)2,2,4-trimethyl-1,2-hydroquinoline, Mobay Corporation, (4)6-ethoxy-1,2-dihydro-2,2,4-trimethylquinoline, Monsanto Chemicals, (5)2,4,6-tris-(N-1,4-dimethylpentyl-4-phenylenediamino)-1,3,5-triazine,Uniroyal Corporation; (6) 2-(4-benzoyl-3-hydroxyphenoxy)ethylacrylate,(7) 2-dodecyl-N-(2,2,6,6-tetra methyl-4-piperidinyl)succinimide, (8)2-dodecyl-N-(1,2,2,6,6-pentamethyl-4-piperidinyl)succinimide, (9)N-(1-acetyl-2,2,6,6-tetramethyl-4-piperidinyl)-2-dodecyl succinimide,all four available from Aldrich Chemicals; (10)2,2,6,6-tetramethyl-4-piperidinyl/βββ'β',-tetramethyl-3,9-(2,4,8,10-tetraoxospiro(5,5)-undecane)diethyl]-1,2,3,4-butane tetracarboxylate, (11)[1,2,2,6,6-pentamethyl-4-piperidinyl/β,ββ'β'-tetramethyl-3,9-(2,4,8,10-tetraoxo-spiro-(5,5)undecane)diethyl]-1,2,3,4-butanetetracarboxylate, (12) [2,2,6,6-tetramethyl-4-piperidinyl)-1,2,3,4-butanetetracarboxylate, all three available from Fairmount Corporation, and(13) nickel dibutyl dithio carbamate, available as UV-Chek AM-105, fromFerro Corporation.

The lightfast antioxidants include for example: (1)antimonydialkylphosphorodithioate, (2) molybdenumoxysulfidedithiocarbamate, both available from Vanderbilt Corporation, (3)(nickel-bis(o-ethyl(3,5-di-tert-butyl-4-hydroxybenzyl) phosphonate, CibaGeigy Corporation, (4) tetra sodium-N-(1,2-dicarboxyethyl)-N-octadecylsulfosuccinamate, American Cyanamid Corporation.

Suitable colorants, present in an effective amount generally of fromabout 1 to about 20, or preferably for example, from 2 to about 10percent by weight, include pigments and dyes, with solvent dyes beingpreferred. Any dye or pigment may be chosen, provided that it is capableof being dispersed or dissolved in the vehicle and is compatible withthe other ink components. Colorant includes pigments, dyes, mixturesthereof, mixtures of dyes, mixtures of pigments, and the like.

Examples of suitable colorants include pigments such as Violet TonerVT-8015 (Paul Uhlich), Paliogen Violet 5100 (BASF), Paliogen Violet 5890(BASF), Permanent Violet VT 2645 (Paul Uhlich), Heliogen Green L8730(BASF), Argyle Green XP-111-S (Paul Uhlich), Brilliant Green Toner GR0991 (Paul Uhlich), Lithol Scarlet D3700 (BASF), Toluidine Red(Aldrich), Scarlet for Thermoplast NSD PS PA (Ugine Kuhlmann of Canada),E.D. Toluidine Red (Aldrich), Lithol Rubine Toner (Paul Uhlich), LitholScarlet 4440 (BASF), Bon Red C (Dominion Color Company), Royal BrilliantRed RD-8192 (Paul Uhlich), Oracet Pink RF (Ciba-Geigy), Paliogen Red3871K (BASF), Paliogen Red 3340 (BASF), Lithol Fast Scarlet L4300(BASF), Heliogen Blue L6900, L7020 (BASF), Heliogen Blue K6902, K6910(BASF), Heliogen Blue D6840, D7080 (BASF), Sudan Blue OS (BASF), NeopenBlue FF4012 (BASF), PV Fast Blue B2G01 (American Hoechst), Irgalite BlueBCA (Ciba-Geigy), Paliogen Blue 6470 (BASF), Sudan II((Red Orange),(Matheson, Colemen Bell), Sudan I((Orange), (Matheson, Colemen Bell),Sudan Orange G (Aldrich), Sudan Orange 220 (BASF), Paliogen Orange 3040(BASF), Ortho Orange OR 2673 (Paul Uhlich), Paliogen Yellow 152,1560(BASF), Lithol Fast Yellow 0991K (BASF), Paliotol Yellow 1840 (BASF),Novoperm Yellow FGL (Hoechst), Permanent Yellow YE 0305 (Paul Uhlich),Lumogen Yellow D0790 (BASF), Suco-Yellow L1250 (BASF), Suco-Yellow D1355(BASF), Suco Fast Yellow D1355, D1351 (BASF), Hostaperm Pink E (AmericanHoechst), Fanal Pink D4830 (BASF), Cinquasia Magenta (Du Pont), PaliogenBlack L0084 (BASF), Pigment Black K801 (BASF), and carbon blacks such asRegal 330® (Cabot), Carbon Black 5250, and Carbon Black 5750 (ColumbiaChemical Company).

Examples of suitable dyes include Pontamine; Food Black 2; CarodirectTurquoise FBL Supra Conc.(Direct Blue 199), available from CarolinaColor and Chemical; Special Fast Turquoise 8 GL Liquid (Direct Blue 86),available from Mobay Chemical; Intrabond Liquid Turquoise GLL (DirectBlue 86), available from Crompton and Knowles; Cibracron Brilliant Red38-A (Reactive Red 4), available from Aldrich Chemical; DrimareneBrilliant Red X-2B (Reactive Red 56), available from Pylam, Inc.;Levafix Brilliant Red E-4B, available from Mobay Chemical; LevafixBrilliant Red E6-BA, available from Mobay Chemical; Procion Red H8B(Reactive Red 31), available from ICI America; Pylam Certified D&C Red#28 (Acid Red 92), available from Pylam; Direct Brill Pink B GroundCrude, available from Crompton and Knowles; Cartasol Yellow GTFPresscake, available from Sandoz, Inc.; Tartrazine Extra Conc. (FD&CYellow #5, Acid Yellow 23), available from Sandoz, Inc.; CarodirectYellow RL (Direct Yellow 86), available from Carolina Color andChemical; Cartasol Yellow GTF Liquid Special 110, available from Sandoz,Inc.; D&C Yellow #10 (Acid Yellow 3), available from Tricon; YellowShade 16948, available from Tricon; Basacid Black X 34, available fromBASF; Carta Black 2GT, available from Sandoz, Inc.; and the like.Particularly preferred are solvent dyes, and within the class of solventdyes, spirit soluble dyes are preferred because of their compatibilitywith the vehicles and dye leveling agents of the present application.Examples of suitable spirit solvent dyes include Neozapon Red 492(BASF), Orasol Red G (Ciba-Geigy), Direct Brilliant Pink B (Crompton -Knolls), Aizen Spilon Red C- BH (Hodagaya Chemical Company), Kayanol Red3BL (Nippon Kayaku Company). Levanol Brilliant Red 3BW (Mobay ChemicalCompany), Levaderm Lemon Yellow (Mobay Chemical Company), Spirit FastYellow 3G, Aizen Spilon Yellow C-GNH (Hodagaya Chemical Company), SiriusSupra Yellow GD 167, Cartasol Brilliant Yellow 4GF (Sandoz), PergasolYellow CGP (Ciba-Geigy), Orasol Black RLP(Ciba-Geigy), Savinyl Black RLS(Sandoz), Dermacarbon 2GT(Sandoz), Pyrazol Black BG (ICI), Morfast BlackConc.A (Morton-Thiokol), Diaazol Black RN Quad (ICI), Orasol Blue GN(Ciba-Geigy), Savinyl Blue GLS (Sandoz), Luxol Blue MBSN(Morton-Thiokol), Sevron Blue 5GMF (ICI), Basacid Blue 750 (BASF), andthe like.

The nonaqueous ink composition may also contain additives such asbiocides, humectants, and the like.

Optional ink additives more specifically include biocides such asDowicil 150, 200, and 75, benzoate salts, sorbate salts, and the like,present in effective amounts, such as for example an amount of fromabout 0.0001 to about 4 percent by weight, and preferably from about0.01 to about 2.0 percent by weight; pH controlling agents such asacids; or bases, phosphate salts, carboxylates salts, sulfite salts,amine salts, and the like, present, for example, in an amount of from 0to about 1 percent by weight and preferably from about 0.01 to about 1percent by weight, based on the weight of the ink components.

The examples of ink components recited herein represent examples, thusother suitable components not specifically recited may also be selectedin embodiments of the present invention.

The inks of the present invention can be prepared by any suitablemethod. A colored semi-solid hot melt ink composition was prepared bymixing 30 percent by weight of a cyclic liquid vehicle having anacoustic-loss value of less than about 40 dB/mm and a boiling point ofgreater than about 150° C., 35 percent by weight of the solid additive,such as a cyclic additive with a melting point of lower than 75° C. andan acoustic-loss value of less than about 60 dB/mm, 20 percent by weightof a liquid crystalline nitrile compound, 5 percent by weight of alighfast UV absorber, 5 percent by weight of lightfast antioxidant and 5percent by weight of a colorant. The mixture can then be heated to atemperature of about 100° C. and stirred for a period of about 60minutes until it forms a homogeneous solution, and subsequently wascooled to 25° C.

The inks of the present invention are particularly suitable for printingprocesses wherein the substrate, such as paper, transparency material,or the like, is heated during the printing process to facilitateformation of the liquid crystalline phase within the ink. Whentransparency substrates are selected, temperatures typically are limitedto a maximum of about 100° C. to about 110° C., since the polyestertypically employed as the base sheet tends to deform at highertemperatures. Specially formulated transparencies and paper substratescan, however, tolerate higher temperatures, and frequently are suitablefor exposure to temperatures of 150° C. or even 200° C. in someinstances. Typical heating temperatures are from about 40° C. to about140° C., and preferably from about 60° C. to about 95° C., although thetemperature can be outside these ranges.

The inks of the present invention are also suitable for use in acousticink jet printing processes. In acoustic ink jet printing, reference anumber of the copending applications and patents recited here, thedisclosures of which have been totally incorporated herein by reference,an acoustic beam exerts a radiation pressure against objects upon whichit impinges. Thus, when an acoustic beam impinges on a free surface ofthe ink of a pool of liquid from beneath, the radiation pressure whichit exerts against the surface of the pool may reach a sufficiently highlevel to release individual droplets of liquid from the pool, despitethe restraining force of surface tension. Focusing the beam on or nearthe surface of the pool intensifies the radiation pressure it exerts fora given amount of input power, reference, for example, IBM TechnicalDisclosure Bulletin, Vol. 16, No. 4, September 1973, pages 1168 to 1170,the disclosure of which is totally incorporated herein by reference.Acoustic ink printers typically comprise one or more acoustic radiatorsfor illuminating the free surface of a pool of liquid ink withrespective acoustic beams. Each of these beams usually is brought tofocus at or near the surface of the reservoir (i.e., the liquid/airinterface). Furthermore, printing conventionally is accomplished byindependently modulating the excitation of the acoustic radiators inaccordance with the input data samples for the image that is to beprinted. This modulation enables the radiation pressure, which each ofthe beams exerts against the free ink surface, to make brief, controlledexcursions to a sufficiently high pressure level for overcoming therestraining force of surface tension. That, in turn, causes individualdroplets of ink to be ejected from the free ink surface on demand at anadequate velocity to cause them to deposit in an image configuration ona nearby recording medium. The acoustic beam may be intensity modulatedor focused/defocused to control the ejection timing, or an externalsource may be used to extract droplets from the acoustically excitedliquid on the surface of the pool on demand. Regardless of the timingmechanism employed, the size of the ejected droplets is determined bythe waist diameter of the focused acoustic beam. Acoustic ink printingis attractive primarily because it does not require the nozzles or thesmall ejection orifices which have caused many of the reliability andpixel placement accuracy problems that conventional drop on demand andcontinuous stream ink jet printers have suffered.

Pixel placement accuracy problems that conventional drop on demand andcontinuous stream ink jet printers have suffered. The size of theejection orifice is a critical design parameter of an ink jet because itdetermines the size of the droplets of ink that the jet ejects. As aresult, the size of the ejection orifice cannot be increased withoutsacrificing resolution. Acoustic printing has increased intrinsicreliability since usually there are no nozzles to clog. Furthermore,small ejection orifices are avoided, so acoustic printing can beperformed with a greater variety of inks than conventional ink jetprinting, including inks having higher viscosities and inks containingpigments and other particulate components. Acoustic ink printersembodying printheads comprising acoustically illuminated sphericalfocusing lenses can print precisely positioned pixels (picture elements)at resolutions which are sufficient for high quality printing ofrelatively complex images. It has also been determined that the size ofthe individual pixels printed by such a printer can be varied over asignificant range during operation, thereby accommodating, for example,the printing of variably shaded images. Furthermore, the known dropletejector technology can be adapted to a variety of printheadconfigurations, including (1) single ejector embodiments for raster scanprinting, (2) matrix configured ejector arrays for matrix printing, and(3) several different types of pagewidth ejector arrays, ranging from(i) single row, sparse arrays for hybrid forms of parallel/serialprinting to (ii) multiple row staggered arrays with individual ejectorsfor each of the pixel positions or addresses within a pagewidth imagefield (i.e., single ejector/pixel/line) for ordinary line printing. Inkssuitable for acoustic ink jet printing typically are liquid at ambienttemperatures (i.e., about 25° C.), however in other embodiments the inkis in a solid state at ambient temperatures and provision is made forliquefying the ink by heating or any other suitable method prior tointroduction of the ink into the printhead. Images of two or more colorscan be generated by several methods, including by processes wherein asingle printhead launches acoustic waves into pools of different coloredinks. Further information regarding acoustic ink jet printing apparatusand processes is disclosed in, for example, U.S. Pat. No. 4,308,547,U.S. Pat. No. 4,697,195, U.S. Pat. No. 5,028,937, U.S. Pat. No.5,041,849, U.S. Pat. No. 4,751,529, U.S. Pat. No. 4,751,530, U.S. Pat.No. 4,751,534, U.S. Pat. No. 4,801,953, and U.S. Pat. No. 4,797,693, thedisclosures of each of which are totally incorporated herein byreference. The use of focused acoustic beams to eject droplets ofcontrolled diameter and velocity from a free-liquid surface is alsodescribed in J. Appl. Phys., vol. 65, no. 9 (May 1, 1989) and referencestherein, the disclosure of which is totally incorporated herein byreference.

Acoustic-loss Measurements recited herein were measured as follows:samples of various cyclic liquid vehicles and cyclic solid surfaceleveling compounds were placed between two transducers with thetemperature set at 150° C. The samples were allowed to equilibrate at150° C. for five minutes. The two transducers were brought together tomaximize the acoustic signal. The amplitude and the position of thesignals were recorded. The two transducers were then separated by adistance varying from 25.4 microns to 125.4 microns recording each timethe amplitude and the position of the signal. Each measurement wasperformed three times and three samples of the same material weremeasured. The attenuation dB/mm was then calculated by ratioing theamplitude values obtained at different separation distances. The liquidcyclic compounds had dB/mm values of for example, from about 15 to 40,and the solid cyclic compounds had dB/mm values of from about 35 toabout 65. A value of less than 80 dB/mm for the ink composition is ofimportance with respect to acoustic jetting processes.

The optical density measurements recited herein were obtained on aPacificpectrograph Color System. The system consists of two majorcomponents, an optical sensor and a data terminal. The optical sensoremploys a 6 inch integrating sphere to provide diffuse illumination and8 degrees viewing. This sensor can be used to measure both transmissionand reflectance samples. When reflectance samples are measured, aspecular component may be included. A high resolution, full dispersion,grating monochromator was used to scan the spectrum from 380 to 720nanometers. The data terminal features a 12 inch CRT display, numericalkeyboard for selection of operating parameters and the entry oftristimulus values, and an alphanumeric keyboard for entry of productstandard information

The lightfast values of the ink jet images were measured in the Mark VLightfast Tester obtained from Microscal Company, London, England.

The waterfast values of the ink jet images were obtained from theoptical density data recorded before and after washing with hot [50° C.]water for two minutes.

Specific embodiments of the invention will now be described in detail.These examples are intended to be illustrative, and the invention is notlimited to the materials, conditions, or process parameters set forth inthese embodiments. All parts and percentages are by weight unlessotherwise indicated. Temperatures are in degrees Centigrade.

EXAMPLE 1

A black semi-solid hot melt ink composition was prepared by mixing 30percent by weight of the liquid cyclic vehicle1-acetyl-2-methyl-1-cyclopentene, (Aldrich #28,268-5), with anacoustic-loss value of 20 dB/mm and a boiling point of 190° C., 35percent by weight of the cyclic solid additive 2,4,8,10-tetra oxa Spiro[5.5]undecane, (Aldrich #22,061-2), with a melting point of 53° C. andan acoustic-loss value of 35 dB/mm, 20 percent by weight of the nitrileliquid crystalline compound 4'-(pentyloxy)-4-biphenyl carbonitrile,(Aldrich #32,852-9), 5 percent by weight of the UV absorber2-dodecyl-N-(2,2,6,6-tetramethyl-4-piperidinyl) succinimide, (Aldrich#41,317-8), 5 percent by weight of an antioxidant tetrasodium-N-(1,2-dicarboxyethyl)-N-octadecyl sulfosuccinamate, Aerosol 22N,American Cyanamid Corporation, and 5 percent by weight of the colorantOrasol Black RLP (Ciba-Geigy). The resulting mixture was heated to atemperature of about 100° C. and stirred for a period of about 60minutes until it formed a homogeneous solution, and subsequently wascooled to 25° C. The resulting black ink had an acoustic loss value of39 dB/mm and a viscosity of 5.1 cps at 150° C.

EXAMPLE 2

A blue semi-solid hot melt ink composition was prepared by mixing 30percent by weight of the liquid cyclic vehicle1-acetyl-2-methyl-1-cyclopentene, (Aldrich #28,268-5), with anacoustic-loss value of 20 dB/mm and a boiling point of 190° C., 35percent by weight of the solid paper additive 2,4,8,10-tetra oxa spiro[5.5]undecane, (Aldrich #22,061-2), with a melting point of 53° C. andan acoustic-loss value of 35 dB/mm, 20 percent by weight of the nitrileliquid crystalline compound 4'-(pentyloxy)-4-biphenylcarbonitrile,(Aldrich #32,852-9), 5 percent by weight of the UV absorber2-dodecyl-N-(2,2,6,6-tetramethyl-4-piperidinyl) succinimide, (Aldrich#41,317-8), 5 percent by weight of the antioxidant tetrasodium-N-(1,2-dicarboxyethyl)-N-octadecyl sulfosuccinamate, Aerosol 22N,American Cyanamid Corporation, and 5 percent by weight of the colorantSudan Blue dye (BASF). The resulting mixture was heated to a temperatureof about 100° C. and then stirred for a period of about 60 minute untilit formed a homogeneous solution, and subsequently the solution wascooled to 25° C. The resulting blue ink had an acoustic loss value of 39dB/mm and a viscosity of 5.15 cps at 150° C.

EXAMPLE 3

A yellow semi-solid hot melt ink composition was prepared by mixing 30percent by weight of the liquid cyclic vehicle1-acetyl-2-methyl-1-cyclopentene, (Aldrich #28,268-5), with anacoustic-loss value of 20 dB/mm and a boiling point of 190° C., 35percent by weight of the solid cyclic (2) additive 2,4,8,10-tetra oxaspiro [5.5]undecane, (Aldrich #22,061-2), with a melting point of 53° C.and an acoustic-loss value of 35 dB/mm, 20 percent by weight of thenitrile liquid crystalline compound4'-(pentyloxy)-4-biphenylcarbonitrile, (Aldrich #32,852-9), 5 percent byweight of the UV absorber2-dodecyl-N-(2,2,6,6-tetramethyl-4-piperidinyl) succinimide, (Aldrich#41,317-8), 5 percent by weight of the antioxidanttetrasodium-N-(1,2-dicarboxyethyl)-N-octadecyl sulfosuccinamate, Aerosol22N, American Cyanamid Corporation, and 5 percent by weight of thecolorant Sudan yellow dye (BASF). The resulting mixture was heated to atemperature of about 100° C. and then stirred for a period of about 60minutes until it formed a homogeneous solution, and subsequently thesolution was cooled to 25° C. The resulting yellow ink had an acousticloss value of 38 dB/mm and a viscosity of 5.05 cps at 150° C.

EXAMPLE 4

A red semi-solid hot melt ink composition was prepared by mixing 30percent by weight of the liquid cyclic vehicle1-acetyl-2-methyl-1-cyclopentene, (Aldrich #28,268-5), with anacoustic-loss value of 20 dB/mm and a boiling point of 190° C., 35percent by weight of the solid additive 2,4,8,10-tetra oxa spiro[5.5]undecane, (Aldrich #22,061-2), with a melting point of 53° C. andan acoustic-loss value of 35 dB/mm, 20 percent by weight of the nitrileliquid crystalline compound 4'-(pentyloxy)-4-biphenyl carbonitrile,(Aldrich #32,852-9), 5 percent by weight of the UV absorber2-dodecyl-N-(2,2,6,6-tetramethyl-4-piperidinyl) succinimide, (Aldrich#41,317-8), 5 percent by weight of the antioxidanttetrasodium-N-(1,2-dicarboxyethyl)-N-octadecyl sulfosuccinamate, Aerosol22N, American Cyanamid Corporation, and 5 percent by weight of thecolorant Sudan Red dye (BASF). The resulting mixture was heated to atemperature of about 100° C. (degrees Centigrade throughout) and thenstirred for a period of about 60 minutes until it formed a homogeneoussolution, and subsequently the solution was cooled to 25° C. Theresulting yellow ink possessed an acoustic loss value of 38 dB/mm and aviscosity of 5.02 cps at 150° C.

Each of the above prepared four inks were incorporated into an acousticink jet printing test fixture utilizing the ejection mechanism disclosedin J. Appl. Phys. 65(9), May 1, 1989, and references therein, thedisclosure of which are totally incorporated herein by reference. Ajetting frequency of 160 MHz was used to generate drops of about 2picoliters, up to 12 drops per pixel at 600 spi. The images formedexhibited excellent color quality with optical density values of 1.52(Black), 1.54 (Cyan), 1.32 (Magenta), 0.95 (Yellow), and sharp edges,with lightfastness and waterfastness of greater than 98.5 percent, andmore specifically from about 99 to about 99.7.

EXAMPLE 5

A black semi-solid hot melt ink composition was prepared by mixing 30percent by weight of the liquid cyclic vehicle 1,2,2,6,6-pentamethylpiperidine, (Aldrich #27,463-1), with an acoustic-loss value of about 15dB/mm and a boiling point of 188° C., 35 percent by weight of the solidadditive 1,2-bis(4,4-dimethyl-2-oxazolin-2-yl)ethane, (Aldrich#24,309-4), with a melting point of 57° C. and an acoustic-loss value of37 dB/mm, 20 percent by weight of the nitrile liquid crystallinecompound 4-(trans-4-pentyl cyclohexyl) benzonitrile, (Aldrich#37,011-8), 5 percent by weight of the UV absorber[1,2,2,6,6-pentamethyl-4-piperidinyl/β,β,β',β',-tetramethyl-3,9-(2,4,8,10-tetraoxospiro (5,5) undecane)diethyl]-1,2,3,4-butane tetracarboxylate, MixximHALS 63, Fairmount Corporation, 5 percent by weight of the antioxidanttetra sodium-N-(1,2-dicarboxyethyl)-N-octadecyl sulfosuccinamate,Aerosol 22N, American Cyanamid Corporation, and 5 percent by weight ofthe colorant Orasol Black RLP (Ciba-Geigy). The resulting mixture washeated to a temperature of about 100° C. and then stirred for a periodof about 60 minutes until it formed a homogeneous solution, andsubsequently the solution was cooled to 25° C. The resulting black inkhad an acoustic loss value of 39 dB/mm and a viscosity of 5.1 cps at150° C.

EXAMPLE 6

A blue semi-solid hot melt ink composition was prepared by mixing 30percent by weight of the liquid cyclic vehicle butyric anhydride,(Aldrich#18,573-6), with an acoustic-loss value of 18 dB/mm and aboiling point of 205° C., 35 percent by weight of the solid additivestearic anhydride, (Aldrich #28,651-6), with a melting point of 72° C.and an acoustic-loss value of less than about 34 dB/mm, 20 percent byweight of the nitrile liquid crystalline compound4'-(pentyloxy)-4-biphenylcarbonitrile, (Aldrich #32,852-9), 5 percent byweight of the UV absorber 2-dodecyl-N-(2,2,6,6-tetramethyl-4-piperidinyl) succinimide, (Aldrich #41,317-8), 5 percent byweight of the antioxidant tetrasodium-N-(1,2-dicarboxyethyl)-N-octadecylsulfosuccinamate, Aerosol 22N, American Cyanamid Corporation, and 5percent by weight of the colorant Sudan Blue dye (BASF). The resultingmixture was heated to a temperature of about 100° C. and then stirredfor a period of about 60 minutes until it formed a homogeneous solution,and subsequently the solution was cooled to 25° C. The resulting blueink possessed an acoustic loss value of 39 dB/mm and a viscosity of 5.05cps at 150° C.

EXAMPLE 7

A yellow semi-solid hot melt ink composition was prepared by mixing 30percent by weight of the liquid cyclic vehicle butyric anhydride,(Aldrich#18,573-6), with an acoustic-loss value of 18 dB/mm and aboiling point of 205° C., 35 percent by weight of the solid (2)noncyclic additive stearic anhydride, (Aldrich #28,651-6), with amelting point of 72° C. and an acoustic-loss value of less than about 34dB/mm, 20 percent by weight of the nitrile liquid crystalline compound4'-(pentyloxy)-4-biphenylcarbonitrile, (Aldrich #32,852-9), 5 percent byweight of the UV absorber2-dodecyl-N-(2,2,6,6-tetramethyl-4-piperidinyl) succinimide, (Aldrich#41,317-8), 5 percent by weight of the antioxidanttetrasodium-N-(1,2-dicarboxyethyl)-N-octadecyl sulfosuccina mate,Aerosol 22N, American Cyanamid Corporation, and 5 percent by weight ofthe colorant Sudan yellow dye (BASF). The resulting mixture was heatedto a temperature of about 100° C. and then stirred for a period of about60 minutes until it formed a homogeneous solution, and subsequently thesolution was cooled to 25° C. The resulting yellow ink had an acousticloss value of 38 dB/mm and a viscosity of 5.05 cps at 150° C.

EXAMPLE 8

A red semi-solid hot melt ink composition was prepared by mixing 30percent by weight of the liquid cyclic vehicle butyric anhydride,(Aldrich#18,573-6), with an acoustic-loss value of 18 dB/mm and aboiling point of 205° C., 35 percent by weight of the solid paperadditive stearic anhydride, (Aldrich #28,651-6), with a melting point of72° C. and an acoustic-loss value of less than about 34 dB/mm, 20percent by weight of the nitrile liquid crystalline compound4'-(pentyloxy)-4-biphenylcarbonitrile, (Aldrich #32,852-9), the UVabsorber 2-dodecyl-N-(2,2,6,6-tetramethyl-4-piperidinyl) succinimide,(Aldrich #41,317-8), 5 percent by weight of the antioxidanttetrasodium-N-(1,2-dicarboxyethyl)-N-octadecyl sulfosuccina mate,Aerosol 22N, American Cyanamid Corporation, and 5 percent by weight ofthe colorant Sudan Red dye (BASF). The resulting mixture was heated to atemperature of about 100° C. and then stirred for a period of about 60minutes until it formed a homogeneous solution, and subsequently thesolution was cooled to 25° C. The resulting yellow ink had an acousticloss value of 38 dB/mm and a viscosity of 5.02 cps at 150° C.

Each of the above prepared four inks were incorporated into an acousticink jet printing test fixture utilizing the ejection mechanism disclosedin J. Appl. Phys. 65(9), May 1, 1989, and references therein, thedisclosure of which are totally incorporated herein by reference. Ajetting frequency of 160 MHz was used to generate drops of about 2picoliters, up to 12 drops per pixel at 600 spi. The images formedexhibited excellent color quality with optical density values of 1.62(Black), 1.61 (Cyan), 1.33 (Magenta), 0.92 (Yellow), sharp edges, withlightfastness and waterfastness of greater for each, than 97 percent,and more specifically from about 97.3 to about 97.7.

Other modifications of the present invention may occur to those ofordinary skill in the art subsequent to a review of the presentapplication, and these modifications, including equivalents thereof, areintended to be included within the scope of the present invention.

What is claimed is:
 1. An ink composition comprised of (1) a liquidcyclic vehicle (2) a cyclic compound, (3) a liquid crystalline nitrilecompound, (4) a lightfastness UV absorber, (5) a lightfastnessantioxidant, and (6) a colorant.
 2. An ink in accordance with claim 1wherein the colorant is a pigment.
 3. An ink in accordance with claim 1wherein the colorant is a dye.
 4. An ink in accordance with claim 1 withan acoustic-loss value of from about 5 to about 40 dB/mm for said cyclicliquid vehicle, (2) a solid additive cyclic component with a meltingpoint of from about 30 to about 74° C. and an acoustic-loss value offrom about 25 to about 80 dB/mm, and which ink possesses anacoustic-loss value of from about 10 to about 80 dB/mm, and which inkpossesses a viscosity of from about 1 centipoise to about 10 centipoiseat a temperature of from about 125° C. to about 165° C.
 5. An ink inaccordance with claim 1 wherein the additive (2) is a cyclic solidcompound.
 6. A nonaqueous ink in accordance with claim 1 furthercontaining ink additives.
 7. An ink composition comprised of (1) aliquid cyclic vehicle (2) a component with a melting point of from about30° C. to about 74° C., (3) a liquid crystalline nitrile compound, (4) alightfastness component, (5) a lightfastness antioxidant, and (6) acolorant.